CM500 and CM600 public or private IP address assigned to router?

[DigitalDoug]

Will the CM600 support static ip addresses from Comcast Internet? If not do any of their modems work with static ip addresses?

[antinode]

> Will the CM600 support static ip addresses from Comcast Internet?

   Your WAN/Internet address is an argument between your ISP and your
router.  Any cable modem is a disinterested bystander in that
negotiation.

   I know not about Comcast, but, in many cases, an ISP will use DHCP
for a so-called "static" IP address, but will reserve that address for
your device, so the effect is that you always have the same address,
whether it's actually static (configured on your router) or dynamic
(supplied by the ISP).

   If you can find any _router_ which won't easily work with whatever
Comcast does, then I'd be amazed.

[vkdelta]

NO Retail Modem or Gateway device (from NETGEAR or otherwise) will support Static IP. Comcast does not support it. 

Static is ONLY supported on COMCAST leased devices.

I believe they will give either old NETGEAR CG3000DCR or XB3 or may be Xb6 if you have higher speeds and Xb6 has business class SW.